
list3=["张三","李四","王五","马六","吴七"]
print("输入一个姓名")
n = input()
if n in list3:
    print("%s是列表的第%d个元素"%(n,list3.index((n),0, len(list3))+1))
else:
    print("输入的姓名不在列表中")
